A305548 a(n) = 27*n.

0, 27, 54, 81, 108, 135, 162, 189, 216, 243, 270, 297, 324, 351, 378, 405, 432, 459, 486, 513, 540, 567, 594, 621, 648, 675, 702, 729, 756, 783, 810, 837, 864, 891, 918, 945, 972, 999, 1026, 1053, 1080, 1107, 1134, 1161, 1188, 1215, 1242, 1269, 1296, 1323, 1350, 1377, 1404, 1431, 1458, 1485, 1512

Offset: 0

Author

Eric Chen, Jun 05 2018

Keywords

• nonn
• easy

Links

• Eric Chen, Table of n, a(n) for n = 0..1000
• Index entries for linear recurrences with constant coefficients, signature (2,-1).

Crossrefs

For a(n) = k*n: A001489 (k=-1), A000004 (k=0), A001477 (k=1), A005843 (k=2), A008585 (k=3), A008591 (k=9), A008607 (k=25), A252994 (k=26), this sequence (k=27), A135628 (k=28), A195819 (k=29), A249674 (k=30), A135631 (k=31), A174312 (k=32), A044102 (k=36), A085959 (k=37), A169823 (k=60), A152691 (k=64).

Programs

Mathematica

Range[0,2000,27]

PARI

a(n)=27*n

Formula

a(n) = 27*n.

a(n) = A008585(A008591(n)) = A008591(A008585(n)).

G.f.: 27*x/(x-1)^2.

From Elmo R. Oliveira, Apr 10 2025: (Start)

E.g.f.: 27*x*exp(x).

a(n) = 2*a(n-1) - a(n-2). (End)